Finished doing the mod! It's what I was expecting! Removing the cotton and foam and using felt works!!!
The bass goes deeper and became tighter. The mids are more forward, but it didn't loose that signature treble!. Soundstage seems to have increased a bit more and has more airiness. Overall the tonality hasn't changed but certain aspects improved.
I'm a bit confused on exactly what you did. Would you mind posting some pics? :D